Apparatus for terminating wire or other elongated generally rigid elements

ABSTRACT

A termination assembly is disclosed, which termination assembly is adapted to retain an elongated, generally rigid member, such as a wire to a mounting surface. A mounting surface is configured to define a receiving channel, which may include an aperture. A deformable sleeve member is configured to engage the generally rigid member to be retained and the channel in the mounting member. Cooperative deformation of the deformable sleeve and the mounting member will cause the two members to deform to engage one another, thereby securing the generally rigid member to the mounting surface.

This application is a continuation of application Ser. No. 08/104,185,filed Aug. 9, 1993, now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates generally to methods and apparatus forterminating wire or other elongated, generally rigid, elements; and morespecifically relates to mounting systems adapted to secure a wire, orother similar generally rigid member, to a surface. The presentinvention is considered to have particular applicability in securingelements such as spring wire members to a mounting surface. Suchapplications are often found, for example, in spring clutch systems ofthe type used in automotive parking brake mechanisms.

Problems associated with securing a wire element to a mounting surfaceare well known. In many applications where such a mounting is necessary,the wire, and therefore the mounting assembly, will be subjected to hightensile loads. In the above example of a spring clutch for a parkingbrake, the spring wire and the mounting assembly must sustain a highnumber of cycles of high tensile loading. If a wire and associatedmounting are to withstand such loads, the mounting must not inducebending moments into the wire, and must avoid impairing the tensilecapacity of the wire.

An exemplary conventional mounting system utilizes an anchoring plate,having a plurality of teeth or serrations, which is riveted to amounting surface in an overlying relation to the spring wire so as tosecure the spring wire in a fixed position relative to the mountingsurface. An exemplary system of this type is depicted in FIG. 1. Suchsystems, although generally satisfactory when properly implemented,suffer from the deficiency that such systems require significantattention to assure trouble free installations. For example, the processof riveting, or otherwise securing, the anchoring plate to the mountingsurface is difficult to control. If the securing operation placesexcessive force upon the anchoring plate, the wire may be nicked by theserrations, leading to premature failure of the wire under cyclicalloading. Similarly, the application of too little force in securing theanchoring plate will obviously reduce the retaining force, leading to"pulling out" of the spring wire under tensile loading. The difficultyof controlling these processes within desirable limits is exacerbated byvariations in dimensions of the parts of the assembly.

Accordingly, the present invention provides a new method and apparatusfor mounting a wire, or similar elongated, generally rigid member, to asolid mounting surface which provides optimal retention of the wire orsimilar member, and which provides such optimal retention over a muchwider range of component manufacturing tolerances than was availablethrough prior mounting systems.

SUMMARY OF THE INVENTION

The present invention provides a termination assembly for an elongated,generally rigid member, such as wire. The termination assembly isadapted to retain the member to a mounting member or surface. In onepreferred embodiment, the termination assembly in accordance with thepresent invention includes a deformable sleeve member having an aperturewhich is sized and configured to receive at least a portion of the wireto be terminated or "retained". This aperture may be a recess, butpreferably will be a through-hole extending through the sleeve member.In one preferred embodiment, the deformable sleeve member is anelongated member having a generally toroidal cross section.

In this preferred embodiment, the termination assembly also includes amounting member of which at least a portion is deformable. Thisdeformable portion includes a pair of generally opposed sidewalls whichextend to a first side of the mounting member to cooperatively define araised channel. In a particularly preferred embodiment, the channelincludes an aperture or notch formed between the sidewalls defining thechannel. Also in this particularly preferred embodiment, the sidewallswill be generally parallel. The channel is sized and configured toreceive the deformable sleeve with the sleeve extending at leastpartially through the aperture in an un-deformed state. Preferably, a"close clearance" fit will be formed between the undeformed sleevemember and the sidewalls defining the channel. Subsequent deformation ofthe sleeve member and the mounting member, such as through use of apress or orbital riveter, causes deformation of the sleeve member tosecurely engage the wire, and causes cooperative deformation of themounting member and the sleeve member to cause the two members tosecurely engage one another, thereby securing the wire to the mountingmember.

In one preferred implementation of the invention, the wire will beprovided with a rugose surface to improve engagement between thedeformed sleeve member and the wire. In a particularly preferredembodiment, the wire will be provided with a plurality of curvilinearupsets in the exterior surface to provide the desired rugosity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary prior art wire termination system.

FIG. 2 depicts an exemplary wire retaining system in accordance with thepresent invention depicted in an exemplary installation.

FIG. 3A-B depict the component parts of the wire retaining system ofFIG. 2, depicted in FIG. 3A from a side oblique view of the assembledcomponents, and depicted in FIG. 3B in an oblique exploded view.

FIGS. 4A-C depict an exemplary spring wire as may be retained throughuse of the present invention, with upsets formed therein in accordancewith the present invention; depicted in FIG. 4A in a side view of aportion of the elongated spring wire element; depicted in FIG. 4B from aside view depicting a single upset; and depicted in FIG. 4C from a topview of the portion containing the tipsets depicted in FIG. 4A.

FIG. 5 depicts a retaining button used in the exemplary wire retainingsystem of FIG. 2, illustrated in vertical section.

FIG. 6 depicts the wire retaining system of FIG. 1 in partial verticalsection along line 6--6 in FIG. 3A.

FIG. 7 depicts the wire retaining system of FIG. 1 in partial verticalsection along lines 7--7 in FIG. 3A.

FIGS. 8A-B depict the wire retaining system of FIGS. 3A-B after pressingto form a complete assembly.

FIG. 9 depicts and alternative embodiment of a wire retaining system inaccordance with the present invention, illustrated in an exploded,oblique, view.

FIG. 10 depicts the wire retaining system of FIG. 9 after assembly,illustrated partially in vertical section.

FIG. 11 depicts another alternative embodiment of a wire retainingsystem in accordance with the present invention, illustrated partiallyin vertical section.

FIG. 12 depicts the wire retaining system of FIG. 11, after assembly,illustrated partially in vertical section.

DETAIL DESCRIPTIONS OF PREFERRED EMBODIMENTS

Referring now to the drawings in more detail, and particularly to FIGS.2 and 3A-B therein is depicted an exemplary wire retaining system 10 inaccordance with the present invention. Wire retaining system is depictedin FIG. 2 after deformation to form a completed assembly. The inventionwill be described herein in terms of an exemplary embodiment sized andconfigured to secure spring wire, of a type which might be expected tobe found in an automotive parking brake clutch, to a mounting plate.Wire retaining system 10 is depicted in connection with a parking brakelever arm 11. As will be appreciated by those skilled-in-the-art, theinvention is applicable to retaining any of a number of types of wire,or other similar solid elongated members to a solid surface.Accordingly, as used herein, the term "wire" is not to be considered aslimiting upon the scope of the present invention, but is representativeof any of a number of types of elongated, generally rigid elements whichmay be beneficially secured to a surface through use of the presentinvention.

Wire retaining system 10 includes a deformable mounting member 12 and aretaining button 14. In general, deformable mounting member 12 is formedto form extending sidewalls which define an elongated channel 16. Thewire 18 to be retained will be inserted through a central aperture indeformable retaining button 14, and retaining button 14 will be placedwithin elongated channel 16. A press or similar mechanism will then beutilized to swedge the sidewalls defining elongated channel 16 andretaining button 14 together, and to swedge retaining button 14 to wire18 to securely attach wire 18 to deformable mounting member 12. Withthis overview having been provided, specifics of an exemplary preferredembodiment of wire retaining system 10 will be described in greaterdetail.

In a preferred embodiment of the invention intended for use as acomponent of a parking brake spring clutch, the spring wire utilized mayhave, for example, a cross sectional width 17 of approximately 0.125"and a cross sectional height 19 of approximately 0.093". As is known inthe art, such wire will have a tensile strength typically in excess of200,000 psi, and preferably in excess of 225,000 psi.

Deformable mounting member 12 may be a primary structural member itself(such as, for example, a parking brake lever arm 11 ), or may be aseparate member which will be secured to a primary structural member. Ina wire retaining system for retaining a wire (as described above) in aparking brake clutch assembly, deformable mounting member 12 willpreferably be formed of a low carbon steel, such as 1008-1010 steel, andwill preferably have a nominal thickness of approximately 0.060-0.090".As is best seen in FIGS. 2 and 3A-B, deformable mounting member 12 willbe initially deformed to establish upwardly extending sidewalls 20defining elongated channel 16. Mounting member 12 may be deformed todefine elongated channel 16 through a conventional die-stamping process.In this exemplary embodiment, a notch 22 is defined within elongatedchannel 16. Once again, notch 22 may be formed by a conventional diestamping process.

In this depicted preferred embodiment, upstanding sidewalls 20 define anopen end flat separation gap 23 having a flat dimension of approximately0.125-0.135". Flat separation gap 23 facilitates complimentaryengagement with the width of spring wire 18 which will extend throughgap 23. Deformable member 12 has a nominal base plane portion, indicatedgenerally at 24. The following contours will preferably be formed tocause sidewalls 20 to extend only to one side of this base planeportion. In the depicted exemplary embodiment, the top of each sidewallis at an upper deflection point, indicated generally at 25. Mountingmember 12 will preferably be formed to define an upper deflection pointinternal radius 26 of approximately 0.03". The upper deflection pointexternal radius, as indicated generally at 28, may be approximately0.120". Similarly, the lower deflection point external radius, indicatedgenerally at 30, may also be approximately 0.120". The lower deflectionpoint internal radius, indicated generally at 32 will preferably be atleast 0.017". Such radii facilitate the forming of sidewalls 20 into thedesired conformity, while avoiding cracking of the material formingmounting member 12. In one preferred embodiment, upper deflection points25 will each have a maximum extension of a distance 29 above base planesurface 31 which is approximately equal to the average between thethickness of spring wire 18 and the thickness of mounting member 12proximate base plane portion 24. Accordingly, in the describedembodiment, such extension distance 29 will be approximately0.060-0.090. In one preferred embodiment, this results in the materialthickness at the upper extent of sidewalls 20 (adjacent notch 22), beinggenerally centrally aligned with the midpoint of the height 17 of springwire 18, and also preferably with the midpoint of retaining button 14.

In this embodiment, notch 22 will have a width 34 which is generallyuniform along the length of notch 22, and which is preferablyapproximately 0.377". The length 36 of notch 22 will preferably beapproximately 0.752". Notch 22 will preferably be formed proximate theuppermost point of parallel upper deflection point 25. As will beappreciated from the Figures, the forming of notch 22 behind theuppermost point of each upper deflection point internal radius 26provides opposing shoulders 38 at the forward end of notch 22 adjacentseparation gap 23.

At the rearward end of elongated channel 16, is a rear dome portion 40.Rear dome portion 40 is deformed upwardly to define an tipper flatsurface 42 which is elevated by a distance 44 from the upper surface ofbase plane portion surface 31 (maintained as the surface of separationgap 23) of approximately 0.095-0.110". This distance 44 is slightlygreater than the height 19 of spring wire 18 (0.093"). Rear dome portion40 extends between sidewalls 20 to define a general U-shape to channel16. The edge of rear dome portion 40 defines an upset to engage arearward end of retaining button 14.

Referring now to FIG. 2 and to FIGS. 4A-C, therein is depicted thespring wire 18 being secured in the depicted exemplary embodiment. Inone exemplary embodiment, spring wire 18 may have an overall extendedlength several feet, but is cuffed through a plurality of turns, toyield extending, generally opposed, ends 48, 50. As can best be seen inFIGS. 4A and 4C, at least one end 48 will include a plurality of upsets52 to facilitate retention in wire retaining system 10. In thispreferred embodiment, three upsets 52a-c are provided proximate wire end48. Also, in this preferred embodiment, each upset 52a-c extendsgenerally across the entire width 17 of spring wire 18. Upsets will beplaced to lie within retaining button 14 when spring wire 18 andmounting button 14 are engaged with mounting member 12 and to minimizebending moments in spring wire 18. For example, in one configuration,outermost upset 52a is inset approximately 0.35", on center, from endsurface 54 of wire 18. Upset 52c is then preferably inset an additional0.35", on center, from upset 52a, and is preferably located on the samelower surface 56 as upset 52a. Upset 52b is preferably centered betweenupsets 52a and 52c and extends upwardly from the top surface 58 ofspring wire 18.

As can best be seen in FIG. 4C, each upset preferably extends for adepth of between 9% to 25% of the cross sectional height 60 of springwire 18. Most preferably, each upset will extend inwardly forapproximately 14%-19% of the height 19 of spring wire 18. In thedescribed embodiment, each upset will preferably extend for a depth ofapproximately 0.013-0.018". Further, each upset is preferably formedwith a relatively wide radius 60, for example, a radius of approximately0.045". It is important to avoid the establishing of a tight radius orof another surface which might induce an angular deflection point inwire 18. Upsets 52a-c may be formed through a conventional stampingprocess. As is known to the art, during such a process some flattening,resulting in sidewardly protruding extensions 62, may be encountered. Nodetrimental effects result from such extensions 62, and there is no needfor them to be removed from spring wire 18 prior to assembly in wireretaining system 10.

Upsets 52a-c have been depicted on the top and bottom surfaces of springwire 18. Such placement may be varied. For example, where wire having asignificant ratio of width to height (i.e., appreciably greater than 1),is utilized, it may be preferable to place upsets on side surfaces ofthe wire to facilitate use of the smallest possible aperture inretaining button 14 to receive the wire.

Although the preferred embodiment described herein includes a pluralityof upsets, other alternative measures for providing a rugose surface tothe spring wire may also be employed with the present invention. Forexample, in some applications sand blasting or shot peening the endportion of wire 18 may yield satisfactory results. Alternatively,deformation of the wire, such as through the providing of a twist in thewire may also prove satisfactory for some applications.

Referring now to FIG. 5, therein is depicted an exemplary retainingbutton 14 suitable for use with the present invention. Retaining button14 is preferably again formed of medium carbon steel such as C1030-1035steel. In the embodiment configured for use with the wire and mountingplate described herein, retaining button 14 will have an externaldiameter 64 of approximately 0.373-0.375" and a length 66 ofapproximately 0.75". Retaining button will also have a longitudinallyextending aperture 68 centered approximately along the centerline ofbutton 14, such aperture having a diameter 70 of approximately0.155-0.159". Additionally, a small counter sink 72, such as anapproximately 118° counter sink across a diameter of approximately0.255-0.265" proximate aperture 68 may be provided proximate each end ofbutton 14.

To assemble wire retaining system 10, retaining button 14 willpreferably first be slipped over end 50 of wire 18 having upsets 52a-cformed therein. The engaged assembly of wire 18 and retaining button 14will then be engaged with elongated channel 16 formed in deformablemounting member 12. Retaining button 14 will preferably have a closeclearance fit within notch 22. Wire 18 should extend longitudinallybeyond retaining button 14 such that wire 18 extends beneath rear domeportion 40 of channel 16. Preferably, wire 18 will extend approximately0.25" beyond retaining button 14, providing a "tail end" 41 extendingbeneath dome portion 40. When such placement is achieved, a pressingforce will be applied to swedge retaining button 14, mounting member 12and wire 18 together.

In one implementation, a conventional press providing two flat,generally parallel, opposed surfaces may be utilized to perform thedescribed swedging step. In such implementations, with materials asdescribed herein, a press force of approximately 20 tons is required.Alternatively, other apparatus, such as an orbital riveter, as is knownto the art, may be utilized to successfully roll down the contours ofthe described components, and thereby swedge the assembly together.

An exemplary wire retaining system as described herein has been found toprovide substantial improvements in the anchoring of a wire againsttensile load. For example, relative to prior art designs utilized forretaining wire by the assignee of the current invention, as depicted inFIG. 1, a spring wire retaining system substantially as described hereinhas been found to be able to hold approximately four times the tensileload for a given spring wire size.

The shoulders 38 flanking fiat separation gap 23 provide an upset toretain button 14 during tensile loading. Additionally, the engagement ofthe rearwardly extending "tail" of wire 18 with upper surface 44 of reardome portion 40 again serves to further stabilize the positioning ofbutton 14 and to thereby prevent pull-out during high tensile loading.

Referring now to FIGS. 9 and 10, therein is depicted an alternativeembodiment of a wire retention assembly, indicated generally at 80, inaccordance with the present invention. In this illustrative alternativeembodiment, spring wire 18 and retaining button 14 may be of essentialidentical configurations to those described relative to the embodimentof FIGS. 1-8. A different configuration, however, is provided to amounting plate 82. Mounting plate 82 also includes a longitudinalchannel 84 configured to receive wire 18. Channel 84 may, once again, beformed through conventional die stamping techniques, and will preferablyextend to one side of a base plain surface 86 of mounting member 82.Preferably, channel 84 will be deformed from base plain portion 86 for asufficient distance as to have a depth approximately equal to the heightof wire 18.

Mounting member 82 also includes a notch or aperture 88 which ispreferably symmetrically located relative to channel 84. Notch 88 mayhave dimensions essentially identical to those described to notch 22 ofwire retaining system 10. The described structure allows a lower surface87 of channel 84 to form a wire contacting surface, interrupted by thepresence of aperture 88.

Wire termination assembly 80 will be assembled in an analogous manner tothat described relative to wire retention assembly 10. Once wire 18 isinserted into central aperture 68 of retaining button 14, and retainingbutton 14 is engaged with notch 88, with wire 18 lying adjacent lowersurface 87 of channel 84, the parts will be swedged together aspreviously described.

Referring now to FIGS. 11 and 12, therein is depicted yet anotheralternative embodiment of a wire retaining system, indicated generallyat 90, in accordance with the present invention. Wire retaining system90 differs from the previously described embodiments in that it includesa mounting member 92 which does not include a laterally offset portion,but which merely includes an aperture 94. A deformable retaining member96 includes an elongated body portion 98 and a ranged portion 100. Bodyportion 98 is configured to extend through aperture 94 in relativelyclose clearance engagement with the sidewalls defining aperture 94. Bodyportion 98 also includes a generally diametrically aligned aperture 102sized to receive the wire member 104. Flanged portion 100 includesgenerally annular engaging surfaces 106 to engage a first side 108 ofretaining member 92 to limit travel of deformable retaining member 96through aperture 96.

In one exemplary embodiment, where retaining member 96 would beconfigured to retain an approximately 1/8 inch square wire, body portion98 may have a diameter, for example, of approximately 0.5 inch, whileranged portion 100 would have a diameter of approximately 0.625 inch.Retaining member 96 will be formed of low carbon steel. Aperture 102 inretaining member 96 will preferably be offset from contact surface 106of ranged portion 100 for an appropriate distance to facilitate wire 104being retained in engaging contact with an upper surface 110 of mountingmember 92.

As is apparent from the figures, to assemble wire retaining system 90,deformable retaining member 96 is inserted through aperture 94 inmounting member 92, and wire 104 is inserted through aperture 102 inretaining member 96. Retaining member 96 is then deformed, such as byswedging, to secure wire 104 to mounting member 92.

Many modifications and variations may be made in the techniques andstructures described and illustrated herein without departing from thespirit and scope of the present invention. For example, in addition tothe alternatives expressly discussed herein, the method of the presentinvention is equally applicable to the retaining of wire or other solidmembers having different cross sectional conformities, such as round,hexagonal, octagonal, etc. Additionally, other materials may be utilizedfor components herein. For example, for some applications it may besatisfactory to utilize one of various aluminum alloys as a material forretaining button 14 and/or mounting member 12. Accordingly, theembodiments described and illustrated herein are illustrative only andshould not be considered as limitations on the scope of the presentinvention.

What is claimed:
 1. A termination assembly for an elongated, generallyrigid member, comprising:a deformable sleeve member having an aperturetherethrough, said aperture receiving a portion of said elongatedgenerally rigid member; and a mounting member, said mounting memberincluding a deformable portion having a pair of generally opposedsidewalls, each of said sidewalls having a generally conrugated shape,defining a channel therebetween, said channel receiving said deformablesleeve and wire assembly, said deformable portion of said mountingmember and said deformable sleeve cooperatively deformed relative to oneanother to form a single assembly securing said elongated generallyrigid member to said mounting member.
 2. The termination assembly ofclaim 1, wherein said generally opposed sidewalls extend generallyparallel to one another.
 3. The termination assembly of claim 1, whereinsaid generally opposed sidewalls define shoulders which engage saiddeformable sleeve when said deformable sleeve is received within saidchannel.
 4. The termination assembly of claim 1, wherein said sidewallsare coupled by a rear portion configured to receive a rearwardlyextending portion of said elongated, generally rigid member when saiddeformable sleeve is retained within said channel between said generallyopposed sidewalls.
 5. A wire retention assembly, comprising:a deformablemounting surface defining a wire-receiving plane, said deformablemounting surface further comprising a pair of generally opposedsidewalls forming a channel, each of said sidewall having a generallycorrugated shape, extending to a first side of said wire-receivingplane, said deformable mounting surface having a notch formed betweensaid sidewalls; a deformable sleeve member having an aperture receivinga portion of said wire, said deformable sleeve member engaging saidnotch in said mounting surface, said mounting surface and saiddeformable sleeve cooperatively movable from a first state wherein saidsleeve engages said notch with a low clearance fit to a second statewherein said deformable sleeve member is deformed to retain said wire,and wherein said sleeve member is securely engaged with said mountingsurface and thereby secures said wire to said mounting surface.
 6. Thewire retention assembly of claim 5, wherein in said first state saidsidewalls defining said channel extend to said first side of saidwire-receiving plane for a distance approximately equal to at least thethickness of said wire.
 7. The wire retention assembly of claim 6,wherein said sidewalls define an upset which engages a second end ofsaid deformable sleeve member.
 8. The wire retention assembly of claim5, wherein said mounting member further includes a rear sidewallextending to a first side of said wire-receiving plane, said rearsidewall defining a wire contacting surface, said rear sidewallextending in said first state, to said first side for such distance thatsaid wire contacting surface is offset from said wire-receiving plane bya distance equal to at least the dimension of said wire when said wireis placed adjacent said wire receiving plane of said mounting surface.9. The wire retention assembly of claim 8, wherein said rear sidewallestablishes a shoulder which engages a first end of said deformablesleeve member.
 10. The wire retention of claim 5, wherein said wireincludes an end portion having a generally rugose surface.
 11. The wireretention of claim 10, wherein said generally rugose surface comprises aplurality of upsets in the exterior surface of said wire.
 12. A wireretention assembly for retaining a wire having at least a partiallyrugose surface comprising:a mounting member including a deformablemounting surface defining a wire-receiving plane, said mounting surfacedeformable from a first state to a second state, said deformablemounting surface further comprising a pair of generally opposedsidewalls, each of said sidewalls having a generally corrugated shape,extending to a first side of said wire-receiving plane, said generallyopposed sidewalls coupled by a rear surface extending to said first sideof said wire receiving plane to cooperatively form a generally U-shapedchannel, said rear surface extending in said first state to said firstside of said wire-receiving plane for a distance approximately equal toat least the thickness of said wire, said deformable mounting surfaceincluding a first aperture within said channel; a deformable sleevemember deformable from a first state to a second state and having asecond aperture therethrough, said second aperture engaging a portion ofsaid wire, said deformable sleeve member engaged with said secondaperture in such manner that a first portion of said wire engages saidwire receiving plane, and a second portion of said wire extends betweensaid wire receiving plane and said rear portion, wherein said sidewallsand said second aperture cooperatively define an upset which engages afirst end of said deformable sleeve member, said mounting member andsaid deformable sleeve cooperatively deformed to their respective secondstates to securely engage said mounting surface and said deformablesleeve to one another, and to securely engage said wire to saiddeformable surface.
 13. A termination assembly for an elongated,generally rigid, member, comprising:a deformable member having a firstaperture therein, said first aperture receiving a portion of saidelongated generally rigid member and having a generally cylindricalexternal shape in a first state; and an at least partially deformablemounting member, said mounting member having corrugated sidewallsdefining a second aperture therein and having a first state, saiddeformable member partially received within said second aperture, saiddeformable member and said mounting member deformed from said firststates to engage said mounting member and said generally rigid member,and to thereby secure said elongated, generally rigid member to saidmounting member.
 14. The termination assembly of claim 13, wherein saidmounting member further comprises a channel therein, said channelintersecting said second aperture in said mounting member.
 15. Thetermination assembly of claim 13, wherein said deformable membercomprises a first portion adapted to extend through said second aperturein said mounting member, and a second portion sized and configured toavoid passage through said second aperture in said mounting member.